Identifying the Etiology of Post-acute Sequelae SARS-CoV-2 (PASC) Infection

Abstract

The viral illness coronavirus disease 2019 (COVID-19) has affected millions worldwide since its initial discovery in late 2019. After recovering from the primary viral infection, many have found themselves suffering new, ongoing, or recurrent COVID-19 symptoms in a condition referred to as long COVID or post-acute sequelae SARS-CoV-2 (PASC) infection. Presently, little is understood regarding the etiology of PASC. This literature review analyzes current theories of PASC development in adult humans after initial COVID-19 disease. An understanding of PASC’s developmental mechanism will pave the way for better-targeted therapies to treat patients diagnosed with this illness. Proposed PASC origin theories for discussion include: (1) persistent SARS-CoV-2 remains after initial COVID-19 infection; (2) immunosuppression during COVID-19 disease leads to hyperinflammation and subsequent symptoms; (3) microclots cause organ damage. The interplay between these theories reveals future study directions and implications. A deeper understanding of these PASC mechanisms allows research progression towards treatments that directly target the illness at its source.